Well Abandonment And Plugging
For Oil & Gas


Well & Rigless Well Abandonment Solution

Well Abandonment

The key to a successful well plugging and rigless well abandonment is the use of seals that will secure the well long after the abandonment is complete, reducing corporate liability and potential environmental impact. Traditionally elastomer and cement plugs have been used with varying degrees of success and reliability. Due to their material construction they may deteriorate over time, particularly in corrosive environments. Conventional bridge plugs also have very small expansion ratios, limiting their use to wells with restrictions. High expansion plugs, such as inflatable packers, don’t possess the differential pressure capabilities required for many oil well abandonments, nor do they provide a gas tight seal.

BiSN Well Abandonment

With our patented Wel-lok M2M™ technology, we have developed multiple tools for use in plugging and abandonment of oil and gas wells. These tools are known as the Wel-lok M2M TS™ (Tubing Seal) and Wel-lok M2M MXD™ (Maximum Drift). Both tools offer higher expansion ratios than conventional bridge plugs and higher differential pressure ratings than inflatable packers, all while providing a V0 rated, gas tight seal that cement cannot provide. Though their designs are different, the proven BiSN technology behind them is the same.

For more information on our rigless well decommissioning and abandonment services, get in touch with our team today.

Summary Overview of the Wel-lok M2M™ technology

BiSN Wel-lok M2M™ technology consists of utilizing a modified thermite heater to melt a bismuth based alloy that cools and expands on solidification. Some of the advantages of this technology are:

Seals wells with patented metal to metal technology

Heater uses a thermite chemical reaction that is non-explosive, no special licenses or handling permits required

Can be deployed on any standard wireline without special connection

Bismuth has a viscosity similar to water when melted in the liquid state allowing it to flow into the smallest of areas including cement micro-annuli

Bismuth has a density 10 times that of water allowing the alloy to displace wellbore fluids

Bismuth expands on solidification which creates a V0 gas tight seal in accordance with ISO 14310

Bismuth is non-corrosive, environmentally friendly and is not affected by H2S, CO2 or acid washes

The seal is created within minutes and ready to test within one hour

Application of The Wel-lok M2M MXD™ technology for Abandonment

This Wel-lok M2M™ application was the first use of this new technology. It was developed to overcome the shortcomings of traditional methods of bridge plugs using cement. It quickly became apparent that this innovative technology is superior to the standard methods both when compared by speed and cost. It can be run on a wire line or a slick line and can pass through small restrictions such as damaged or crushed casing, yet still set the gas tight plug due to the larger drift than conventional bridge plugs.


In an effort to increase the expansion ratio beyond even that of the original TS without compromising pressure differential and gas tight sealing capabilities, BiSN developed the Wel-lok M2M™ MXD tool. The use of a bailer to carry the bismuth based alloy downhole in shot form allows for a smaller diameter tool to be run in hole while increasing the expansion ratio of the tool up to 3 times the tool OD.


BiSN tool range

You can view or download a PDF data sheet of all our other tools by clicking the links below.